SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '555790f8b617a7ddb2e8c19831222f062644fb730e7bb01ae854808414bf340b' 
  AND token = 'pNDlrwrHc1Pu2151XbqiycqPXSIk3/IXio9RJpwiNpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}